Hi all,
we developed a custom board with a MPC8280 PowerQuiccII. It has the serial console on SCC3. We already ported the U-boot 0.4.5 (based on the MPC8266 board) to it and it works fine after a Power-on-Reset. The trouble begins when we issue a HRESET. (We usually do this with the BDI2000 box). After this HRESET the serial console occurs to hang randomly. This mean that the U-Boot code hangs in the while loop of serial_putc() function where it waits for the first character to be sent to the console. But unfortunately the BD_SC_READY gets never deasserted. In this situation we tried to reset the CPM manually (with BDI box) once again with the following sequence: - Issue the RESET Command to the CPM - Set register sccm, scce, gsmrh, gsmrl, and psmr for SCC3 according to the settings in serial_init. - Issue the TRX_INIT command to the SCC3. The command was accepted by the CPM (The CPM_CR_FLAG was reset when we re-read the cpcr) We also verified the the dpram parameter portion had the same contents as in the "good working case". - Enable the transmitter and receiver via gsmrl register.
But the serial console did not react and the BD_SC_READY was not cleared. No further HRESET could then solve the problem. Only after POR the console showed some output again.
This leads us to the impression that somehow the CPM/SCC3 could not properly communicate with the CoreCPU. Does anybody experienced a similar problem?
Any hints would be very much appreciated.
Kind regards, Georg